Redox proteomics of the inflammatory secretome identifies a common set of redoxins and other glutathionylated proteins released in inflammation, influenza virus infection and oxidative stress

Protein cysteines can form transient disulfides with glutathione (GSH), resulting in the production of glutathionylated proteins, and this process is regarded as a mechanism by which the redox state of the cell can regulate protein function. Most studies on redox regulation of immunity have focused on intracellular proteins. In this study we have used redox proteomics to identify those proteins released in glutathionylated form by macrophages stimulated with lipopolysaccharide (LPS) after pre-loading the cells with biotinylated GSH. Of the several proteins identified in the redox secretome, we have selected a number for validation. Proteomic analysis indicated that LPS stimulated the release of peroxiredoxin (PRDX) 1, PRDX2, vimentin (VIM), profilin1 (PFN1) and thioredoxin 1 (TXN1). For PRDX1 and TXN1, we were able to confirm that the released protein is glutathionylated. PRDX1, PRDX2 and TXN1 were also released by the human pulmonary epithelial cell line, A549, infected with influenza virus. The release of the proteins identified was inhibited by the anti-inflammatory glucocorticoid, dexamethasone (DEX), which also inhibited tumor necrosis factor (TNF)-α release, and by thiol antioxidants (N-butanoyl GSH derivative, GSH-C4, and N-acetylcysteine (NAC), which did not affect TNF-α production. The proteins identified could be useful as biomarkers of oxidative stress associated with inflammation, and further studies will be required to investigate if the extracellular forms of these proteins has immunoregulatory functions

3D printed tissue engineered model for bone invasion of oral cancer

Recent advances in three-dimensional printing technology have led to a rapid expansion of its applications in tissue engineering. The present study was designed to develop and characterize an in vitro multi-layered human alveolar bone, based on a 3D printed scaffold, combined with tissue engineered oral mucosal model. The objective was to incorporate oral squamous cell carcinoma (OSCC) cell line spheroids to the 3D model at different anatomical levels to represent different stages of oral cancer. Histological evaluation of the 3D tissue model revealed a tri-layered structure consisting of distinct epithelial, connective tissue, and bone layers; replicating normal oral tissue architecture. The mucosal part showed a well-differentiated stratified oral squamous epithelium similar to that of the native tissue counterpart, as demonstrated by immunohistochemistry for cytokeratin 13 and 14. Histological assessment of the cancerous models demonstrated OSCC spheroids at three depths including supra-epithelial level, sub-epithelial level, and deep in the connective tissue-bone interface. The 3D tissue engineered composite model closely simulated the native oral hard and soft tissues and has the potential to be used as a valuable in vitro model for the investigation of bone invasion of oral cancer and for the evaluation of novel diagnostic or therapeutic approaches to manage OSCC in the future

Survey of both hepatitis B virus (HBsAg) and hepatitis C virus (HCV-Ab) coinfection among HIV positive patients

<p>Abstract</p> <p>Background</p> <p>HIV, HBVand HCV is major public health concerns. Because of shared routes of transmission, HIV-HCV coinfection and HIV-HBV coinfection are common. HIV-positive individuals are at risk of coinfection with HBV and HCV infections. The prevalence rates of coinfection with HBV and HCV in HIV-patients have been variable worldwide depending on the geographic regions, and the type of exposure.</p> <p>Aim</p> <p>This study aimed to examine HBV and HCV coinfection serologically and determine the shared and significant factors in the coinfection of HIV-positive patients.</p> <p>Methods</p> <p>This descriptive, cross-sectional study was carried out on 391 HIV-positive patients including 358 males and 33 females in Lorestan province, west Iran, to survey coinfection with HBsAg and anti-HCV. The retrospective demographic data of the subjects was collected and the patients' serums were analyzed by ELISA kits including HBsAg and anti-HCV. The collected data was analyzed with SPSS software (15) and Chi-square. Fisher's exact test with 5% error intervals was used to measure the correlation of variables and infection rates.</p> <p>Results</p> <p>The results of the study indicated that the prevalence of coinfection in HIV-positive patients with hepatitis viruses was 94.4% (370 in 391), out of whom 57 (14.5%) cases were HBsAg positive, 282 (72%) cases were anti-HCV positive, and 31 (7.9%) cases were both HBsAg and anti-HCV positive.</p> <p>Conclusion</p> <p>There was a significant correlation between coinfection with HCV and HBV and/or both among HIV-positive patients depending on different variables including sex, age, occupation, marital status, exposure to risk factors.(p < 0.001).</p

Bi-directional cell-pericellular matrix interactions direct stem cell fate

Modifiable hydrogels have revealed tremendous insight into how physical characteristics of cells’ 3D environment drive stem cell lineage specification. However, in native tissues, cells do not passively receive signals from their niche. Instead they actively probe and modify their pericellular space to suit their needs, yet the dynamics of cells’ reciprocal interactions with their pericellular environment when encapsulated within hydrogels remains relatively unexplored. Here, we show that human bone marrow stromal cells (hMSC) encapsulated within hyaluronic acid-based hydrogels modify their surroundings by synthesizing, secreting and arranging proteins pericellularly or by degrading the hydrogel. hMSC’s interactions with this local environment have a role in regulating hMSC fate, with a secreted proteinaceous pericellular matrix associated with adipogenesis, and degradation with osteogenesis. Our observations suggest that hMSC participate in a bi-directional interplay between the properties of their 3D milieu and their own secreted pericellular matrix, and that this combination of interactions drives fate

Zinc Coordination Is Required for and Regulates Transcription Activation by Epstein-Barr Nuclear Antigen 1

Epstein-Barr Nuclear Antigen 1 (EBNA1) is essential for Epstein-Barr virus to immortalize naïve B-cells. Upon binding a cluster of 20 cognate binding-sites termed the family of repeats, EBNA1 transactivates promoters for EBV genes that are required for immortalization. A small domain, termed UR1, that is 25 amino-acids in length, has been identified previously as essential for EBNA1 to activate transcription. In this study, we have elucidated how UR1 contributes to EBNA1's ability to transactivate. We show that zinc is necessary for EBNA1 to activate transcription, and that UR1 coordinates zinc through a pair of essential cysteines contained within it. UR1 dimerizes upon coordinating zinc, indicating that EBNA1 contains a second dimerization interface in its amino-terminus. There is a strong correlation between UR1-mediated dimerization and EBNA1's ability to transactivate cooperatively. Point mutants of EBNA1 that disrupt zinc coordination also prevent self-association, and do not activate transcription cooperatively. Further, we demonstrate that UR1 acts as a molecular sensor that regulates the ability of EBNA1 to activate transcription in response to changes in redox and oxygen partial pressure (pO2). Mild oxidative stress mimicking such environmental changes decreases EBNA1-dependent transcription in a lymphoblastoid cell-line. Coincident with a reduction in EBNA1-dependent transcription, reductions are observed in EBNA2 and LMP1 protein levels. Although these changes do not affect LCL survival, treated cells accumulate in G0/G1. These findings are discussed in the context of EBV latency in body compartments that differ strikingly in their pO2 and redox potential

MicroMotility: State of the art, recent accomplishments and perspectives on the mathematical modeling of bio-motility at microscopic scales

Mathematical modeling and quantitative study of biological motility (in particular, of motility at microscopic scales) is producing new biophysical insight and is offering opportunities for new discoveries at the level of both fundamental science and technology. These range from the explanation of how complex behavior at the level of a single organism emerges from body architecture, to the understanding of collective phenomena in groups of organisms and tissues, and of how these forms of swarm intelligence can be controlled and harnessed in engineering applications, to the elucidation of processes of fundamental biological relevance at the cellular and sub-cellular level. In this paper, some of the most exciting new developments in the fields of locomotion of unicellular organisms, of soft adhesive locomotion across scales, of the study of pore translocation properties of knotted DNA, of the development of synthetic active solid sheets, of the mechanics of the unjamming transition in dense cell collectives, of the mechanics of cell sheet folding in volvocalean algae, and of the self-propulsion of topological defects in active matter are discussed. For each of these topics, we provide a brief state of the art, an example of recent achievements, and some directions for future research

The effect of root confinement and calcium stress on the physiology, morphology and cation nutrition in tomatoes (Lycopersicon esculentum Mill.)

Five pot experiments using nutrient solution culture were conducted in a glasshouse where the day and night temperatures were 25±5°C and l8±3°C respectively. Tomato (Lycopersicon esculentum Mill.) plants were trained as a single main stem except those in experiment IV where the lateral shoots were left to grow. For the purpose of this study different glasshouse tomato cu1tivars (Eurovite, Nemarex, Lincross and Angela) were used. To provide different degrees of confinement to the root system, plants were range of container sizes (0.025, 0.05, 0.1, 2.0 l) and compared with nonconfined plants (4.5 l). Other treatments involved releasing the roots after a period of confinement in experiment II, and calcium deficient treatments in combination with root confinement treatments in experiment V using radioactive calcium. The dry weights of roots, stems, leaves and fruits, total leaf surface area, leaf number, root length and root number were measured as well as uptake of potassium, calcium and magnesium. Growing plants under root confinement conditions retarded the growth of vegetative parts in all cultivars. The dry weight of leaves, stems and roots was reduced while that of fruits was not affected. Root confinement was also associated with an increase in the shoot:root and top:root ratios compared with the non confined plants. Releasing the roots after a period of confinement increased the dry weight of the vegetative parts with no effect on the dry weight of fruits. The shoot:root ratio in confined-released plants remained as high as the continuously confined plants although the roots were not under physical confinement particularly when they were released to 2.0 l container. It appears that the effect of root confinement is not a simple physical stress to the roots but also involves some physiological effects through the changes in pattern of the distribution of dry matter between the root and the shoot. During the vegetative stage of growth root confinement increased the proportion of dry weight of stems and reduced that of leaves compared with the non confined plants. After the transition to the reproductive phase, plants showed a new pattern of dry weight distribution mainly brought about by the growth of fruits. The increase in the proportion of dry weight allocated to the top of confined plants was not equally shared by all top components. The proportion of the stems and fruits increased while that of leaves decreased. Physical confinement of the roots reduced the dry weight of lateral shoots but had no effect on the relative partitioning of dry weight between the main stem and the lateral shoots. Root confinement changed the morphology of the leaves. The total and average leaf surface area of confined plants were smaller than those of non confined plants. The concentration of chlorophylls a and b in the leaves of confined plants, in particular Eurovite increased, and the leaves became thicker or denser. These changes in the leaf morphology may have increased the photosynthetic rate of the unit leaf surf ace area and ultimately increased its production of dry matter. Root morphology also changed in response to physical confinement of the root. Confined root systems were more branched, and when the confined roots were released to larger containers the number of lateral roots increased rapidly resulting in a greater ratio of root number:root length compared with those of continuously confined and non confined roots. Confined plants took up smaller amounts of K, Ca or Mg compared with the non confined plants. But when the mineral(s) uptake was expressed on the basis of the amount of mineral(s) absorbed by unit root length or root branch, confined plants showed a greater ability to absorb mineral(s) than non confined plants. The concentration of K in the leaves was not affected by root confinement treatments whereas the concentrations of Ca and Mg were lower in the leaves of confined plants than those whose roots were not confined. However, the lower concentrations of Ca and Mg in leaves of confined plants were higher than the optimum concentration suggested for tomato leaves by Ward (1963). The concentration of minerals in the fruits was the same in all treatments. Root confinement interfered with the translocation of Ca from the root to plant tops. Fractionation of root Ca showed that the majority of Ca was in the acid soluble form (Ca-oxalate, phosphate and carbonate). The possible mechanisms for this accumulation of Ca in the confined roots were suggested. Angela plants were more efficient in utilizing K while those of Eurovite were efficient in utilizing Ca. Root confinement increased the efficiency of utilization of K and Ca in both cultivars. It is concluded therefore that efficiency of mineral utilization is sensitive to environmental as well as to genetic factors. Both calcium treatments (+Ca and -Ca) resulted in a remobilization of radioactive calcium previously deposited in the plant tissues. However, the amounts of Ca remobilized were very small and could not prevent the development of calcium deficiency symptoms in different plant organs, particularly in the non confined plants. Confined plants under calcium deficiency conditions delayed the initiation and development of calcium deficiency symptoms on the leaves and fruits by at least five days compared with the corresponding plants with non confined roots. It is concluded that root confinement could be used as a technique to reduce the risk of sudden shortage of calcium supply in the growing medium. Blossom end rot (BER) in tomato fruits is directly related to the lower concentration of Ca in the fruits, and any factor(s) which may directly or indirectly affect the Ca uptake and/or translocation could enhance the development of this disorder. Angela plants under calcium deficiency conditions showed the symptoms of BER earlier and more severely than similar plants of Eurovite. These variations between the two cultivars were related to the ability of the cultivar to remobilize the previously deposited Ca from different plant tissues

Nanoscale template for the growth of one-dimensional nanostructures

The functionalization of the anisotropic Ag(110) surface with a self-assembled silicon nanostripe grating prior to Co deposition has been studied in situ with scanning tunneling microscopy. At room temperature, Co atoms are adsorbed on top of the silicon nanostructures. As the diffusion rate of Co into the Si nanostripes is very low at this temperature, the formation of well-organized, identical Co nanolines arranged in parallel rows is observed. Upon annealing at 100 °C, Co atoms massively diffuse into the nanostripes, leading to the destruction of the Si array. The early stages of growth at room temperature indicate that the parallel Co nanolines are coupled and display short-range interaction. Our results show that the Ag(110) surface covered with a silicon nanostripe grating can be used as a template for the growth of identical and well-ordered one-dimensional nanostructures of various materials